first commit for chrg

2025-08-16 22:58:22 +08:00
commit 52a3ed5862
2306 changed files with 1021208 additions and 0 deletions
@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2006-2024 RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author      Notes
+ * 2010-11-17     yi.qiu      first version
+ */
+
+#include <rtthread.h>
+#include <rtm.h>
+
+#include "dlmodule.h"
+
+/**
+ * @brief  look up the address of a symbol in a dynamically loaded shared library.
+ *
+ * @param  handle the handle returned by dlopen() when the library was previously loaded.
+ * @param  symbol A string containing the name of the symbol to locate.
+ * @return void* On success, it returns a pointer to the symbol. Otherwise, it returns RT_NULL.
+ *
+ * @note   This function is an API of POSIX standard, which is commonly used in conjunction with dlopen() to retrieve function pointers from shared libraries.
+ *         the input symbol name, which can be the name of a function or variable, is compared with each symbol
+ *         in the module symbol table. if the same symbol is found, return its address.
+ */
+void* dlsym(void *handle, const char* symbol)
+{
+    int i;
+    struct rt_dlmodule *module;
+
+    RT_ASSERT(handle != RT_NULL);
+
+    module = (struct rt_dlmodule *)handle;
+
+    for(i=0; i<module->nsym; i++)
+    {
+        if (rt_strcmp(module->symtab[i].name, symbol) == 0)
+            return (void*)module->symtab[i].addr;
+    }
+
+    return RT_NULL;
+}
+RTM_EXPORT(dlsym)